z image distill

This commit is contained in:
Artiprocher
2025-12-03 11:20:49 +08:00
parent 5065c9ef6a
commit 4a80e9c179
8 changed files with 185 additions and 26 deletions

View File

@@ -101,7 +101,7 @@ class FlowMatchScheduler():
return sigmas, timesteps
@staticmethod
def set_timesteps_z_image(num_inference_steps=100, denoising_strength=1.0, shift=None):
def set_timesteps_z_image(num_inference_steps=100, denoising_strength=1.0, shift=None, target_timesteps=None):
sigma_min = 0.0
sigma_max = 1.0
shift = 3 if shift is None else shift
@@ -110,6 +110,11 @@ class FlowMatchScheduler():
sigmas = torch.linspace(sigma_start, sigma_min, num_inference_steps + 1)[:-1]
sigmas = shift * sigmas / (1 + (shift - 1) * sigmas)
timesteps = sigmas * num_train_timesteps
if target_timesteps is not None:
target_timesteps = target_timesteps.to(dtype=timesteps.dtype, device=timesteps.device)
for timestep in target_timesteps:
timestep_id = torch.argmin((timesteps - timestep).abs())
timesteps[timestep_id] = timestep
return sigmas, timesteps
def set_training_weight(self):
@@ -118,6 +123,10 @@ class FlowMatchScheduler():
y = torch.exp(-2 * ((x - steps / 2) / steps) ** 2)
y_shifted = y - y.min()
bsmntw_weighing = y_shifted * (steps / y_shifted.sum())
if len(self.timesteps) != 1000:
# This is an empirical formula.
bsmntw_weighing = bsmntw_weighing * (len(self.timesteps) / steps)
bsmntw_weighing = bsmntw_weighing + bsmntw_weighing[1]
self.linear_timesteps_weights = bsmntw_weighing
def set_timesteps(self, num_inference_steps=100, denoising_strength=1.0, training=False, **kwargs):

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@@ -31,3 +31,89 @@ def DirectDistillLoss(pipe: BasePipeline, **inputs):
inputs["latents"] = pipe.step(pipe.scheduler, progress_id=progress_id, noise_pred=noise_pred, **inputs)
loss = torch.nn.functional.mse_loss(inputs["latents"].float(), inputs["input_latents"].float())
return loss
class TrajectoryImitationLoss(torch.nn.Module):
def __init__(self):
super().__init__()
self.initialized = False
def initialize(self, device):
import lpips # TODO: remove it
self.loss_fn = lpips.LPIPS(net='alex').to(device)
self.initialized = True
def fetch_trajectory(self, pipe: BasePipeline, timesteps_student, inputs_shared, inputs_posi, inputs_nega, num_inference_steps, cfg_scale):
trajectory = [inputs_shared["latents"].clone()]
pipe.scheduler.set_timesteps(num_inference_steps, target_timesteps=timesteps_student)
models = {name: getattr(pipe, name) for name in pipe.in_iteration_models}
for progress_id, timestep in enumerate(pipe.scheduler.timesteps):
timestep = timestep.unsqueeze(0).to(dtype=pipe.torch_dtype, device=pipe.device)
noise_pred = pipe.cfg_guided_model_fn(
pipe.model_fn, cfg_scale,
inputs_shared, inputs_posi, inputs_nega,
**models, timestep=timestep, progress_id=progress_id
)
inputs_shared["latents"] = pipe.step(pipe.scheduler, progress_id=progress_id, noise_pred=noise_pred.detach(), **inputs_shared)
trajectory.append(inputs_shared["latents"].clone())
return pipe.scheduler.timesteps, trajectory
def align_trajectory(self, pipe: BasePipeline, timesteps_teacher, trajectory_teacher, inputs_shared, inputs_posi, inputs_nega, num_inference_steps, cfg_scale):
loss = 0
pipe.scheduler.set_timesteps(num_inference_steps, training=True)
models = {name: getattr(pipe, name) for name in pipe.in_iteration_models}
for progress_id, timestep in enumerate(pipe.scheduler.timesteps):
timestep = timestep.unsqueeze(0).to(dtype=pipe.torch_dtype, device=pipe.device)
progress_id_teacher = torch.argmin((timesteps_teacher - timestep).abs())
inputs_shared["latents"] = trajectory_teacher[progress_id_teacher]
noise_pred = pipe.cfg_guided_model_fn(
pipe.model_fn, cfg_scale,
inputs_shared, inputs_posi, inputs_nega,
**models, timestep=timestep, progress_id=progress_id
)
sigma = pipe.scheduler.sigmas[progress_id]
sigma_ = 0 if progress_id + 1 >= len(pipe.scheduler.timesteps) else pipe.scheduler.sigmas[progress_id + 1]
if progress_id + 1 >= len(pipe.scheduler.timesteps):
latents_ = trajectory_teacher[-1]
else:
progress_id_teacher = torch.argmin((timesteps_teacher - pipe.scheduler.timesteps[progress_id + 1]).abs())
latents_ = trajectory_teacher[progress_id_teacher]
target = (latents_ - inputs_shared["latents"]) / (sigma_ - sigma)
loss = loss + torch.nn.functional.mse_loss(noise_pred.float(), target.float()) * pipe.scheduler.training_weight(timestep)
return loss
def compute_regularization(self, pipe: BasePipeline, trajectory_teacher, inputs_shared, inputs_posi, inputs_nega, num_inference_steps, cfg_scale):
inputs_shared["latents"] = trajectory_teacher[0]
pipe.scheduler.set_timesteps(num_inference_steps)
models = {name: getattr(pipe, name) for name in pipe.in_iteration_models}
for progress_id, timestep in enumerate(pipe.scheduler.timesteps):
timestep = timestep.unsqueeze(0).to(dtype=pipe.torch_dtype, device=pipe.device)
noise_pred = pipe.cfg_guided_model_fn(
pipe.model_fn, cfg_scale,
inputs_shared, inputs_posi, inputs_nega,
**models, timestep=timestep, progress_id=progress_id
)
inputs_shared["latents"] = pipe.step(pipe.scheduler, progress_id=progress_id, noise_pred=noise_pred.detach(), **inputs_shared)
image_pred = pipe.vae_decoder(inputs_shared["latents"])
image_real = pipe.vae_decoder(trajectory_teacher[-1])
loss = self.loss_fn(image_pred.float(), image_real.float())
return loss
def forward(self, pipe: BasePipeline, inputs_shared, inputs_posi, inputs_nega):
if not self.initialized:
self.initialize(pipe.device)
with torch.no_grad():
pipe.scheduler.set_timesteps(8)
timesteps_teacher, trajectory_teacher = self.fetch_trajectory(inputs_shared["teacher"], pipe.scheduler.timesteps, inputs_shared, inputs_posi, inputs_nega, 50, 2)
timesteps_teacher = timesteps_teacher.to(dtype=pipe.torch_dtype, device=pipe.device)
loss_1 = self.align_trajectory(pipe, timesteps_teacher, trajectory_teacher, inputs_shared, inputs_posi, inputs_nega, 8, 1)
loss_2 = self.compute_regularization(pipe, trajectory_teacher, inputs_shared, inputs_posi, inputs_nega, 8, 1)
loss = loss_1 + loss_2
return loss

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@@ -13,27 +13,3 @@ accelerate launch examples/z_image/model_training/train.py \
--lora_rank 32 \
--use_gradient_checkpointing \
--dataset_num_workers 8
# Z-Image-Turbo is a distilled model.
# After training, it loses its distillation-based acceleration capability,
# leading to degraded generation quality at fewer inference steps.
# This issue can be mitigated by using a pre-trained LoRA model to assist the training process.
# accelerate launch examples/z_image/model_training/train.py \
# --dataset_base_path data/example_image_dataset \
# --dataset_metadata_path data/example_image_dataset/metadata.csv \
# --max_pixels 1048576 \
# --dataset_repeat 50 \
# --model_id_with_origin_paths "Tongyi-MAI/Z-Image-Turbo:transformer/*.safetensors,Tongyi-MAI/Z-Image-Turbo:text_encoder/*.safetensors,Tongyi-MAI/Z-Image-Turbo:vae/diffusion_pytorch_model.safetensors" \
# --learning_rate 1e-4 \
# --num_epochs 5 \
# --remove_prefix_in_ckpt "pipe.dit." \
# --output_path "./models/train/Z-Image-Turbo_lora" \
# --lora_base_model "dit" \
# --lora_target_modules "to_q,to_k,to_v,to_out.0,w1,w2,w3" \
# --lora_rank 32 \
# --preset_lora_path "models/ostris/zimage_turbo_training_adapter/zimage_turbo_training_adapter_v1.safetensors" \
# --preset_lora_model "dit" \
# --use_gradient_checkpointing \
# --dataset_num_workers 8

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@@ -0,0 +1,23 @@
# Z-Image-Turbo is a distilled model.
# After training, it loses its distillation-based acceleration capability,
# leading to degraded generation quality at fewer inference steps.
# This issue can be mitigated by using a pre-trained LoRA model to assist the training process.
# https://www.modelscope.cn/models/ostris/zimage_turbo_training_adapter
accelerate launch examples/z_image/model_training/train.py \
--dataset_base_path data/example_image_dataset \
--dataset_metadata_path data/example_image_dataset/metadata.csv \
--max_pixels 1048576 \
--dataset_repeat 50 \
--model_id_with_origin_paths "Tongyi-MAI/Z-Image-Turbo:transformer/*.safetensors,Tongyi-MAI/Z-Image-Turbo:text_encoder/*.safetensors,Tongyi-MAI/Z-Image-Turbo:vae/diffusion_pytorch_model.safetensors" \
--learning_rate 1e-4 \
--num_epochs 5 \
--remove_prefix_in_ckpt "pipe.dit." \
--output_path "./models/train/Z-Image-Turbo_lora_differential" \
--lora_base_model "dit" \
--lora_target_modules "to_q,to_k,to_v,to_out.0,w1,w2,w3" \
--lora_rank 32 \
--preset_lora_path "models/ostris/zimage_turbo_training_adapter/zimage_turbo_training_adapter_v1.safetensors" \
--preset_lora_model "dit" \
--use_gradient_checkpointing \
--dataset_num_workers 8

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@@ -0,0 +1,18 @@
from diffsynth.pipelines.z_image import ZImagePipeline, ModelConfig
import torch
pipe = ZImagePipeline.from_pretrained(
torch_dtype=torch.bfloat16,
device="cuda",
model_configs=[
ModelConfig(model_id="Tongyi-MAI/Z-Image-Turbo", origin_file_pattern="transformer/*.safetensors"),
ModelConfig(model_id="Tongyi-MAI/Z-Image-Turbo", origin_file_pattern="text_encoder/*.safetensors"),
ModelConfig(model_id="Tongyi-MAI/Z-Image-Turbo", origin_file_pattern="vae/diffusion_pytorch_model.safetensors"),
],
tokenizer_config=ModelConfig(model_id="Tongyi-MAI/Z-Image-Turbo", origin_file_pattern="tokenizer/"),
)
pipe.load_lora(pipe.dit, "./models/train/Z-Image-Turbo_lora_differential/epoch-4.safetensors")
prompt = "a dog"
image = pipe(prompt=prompt, seed=42, rand_device="cuda")
image.save("image.jpg")

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@@ -0,0 +1,18 @@
accelerate launch examples/z_image/model_training/train.py \
--dataset_base_path data/example_image_dataset \
--dataset_metadata_path data/example_image_dataset/metadata.csv \
--max_pixels 1048576 \
--dataset_repeat 50 \
--model_id_with_origin_paths "Tongyi-MAI/Z-Image-Turbo:transformer/*.safetensors,Tongyi-MAI/Z-Image-Turbo:text_encoder/*.safetensors,Tongyi-MAI/Z-Image-Turbo:vae/diffusion_pytorch_model.safetensors" \
--learning_rate 1e-4 \
--num_epochs 5 \
--remove_prefix_in_ckpt "pipe.dit." \
--output_path "./models/train/Z-Image-Turbo_lora_distill" \
--lora_base_model "dit" \
--lora_target_modules "to_q,to_k,to_v,to_out.0,w1,w2,w3" \
--lora_rank 32 \
--lora_checkpoint "./models/train/Z-Image-Turbo_lora/epoch-4.safetensors" \
--use_gradient_checkpointing \
--dataset_num_workers 8 \
--task "trajectory_imitation" \
--save_steps 10

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@@ -0,0 +1,18 @@
from diffsynth.pipelines.z_image import ZImagePipeline, ModelConfig
import torch
pipe = ZImagePipeline.from_pretrained(
torch_dtype=torch.bfloat16,
device="cuda",
model_configs=[
ModelConfig(model_id="Tongyi-MAI/Z-Image-Turbo", origin_file_pattern="transformer/*.safetensors"),
ModelConfig(model_id="Tongyi-MAI/Z-Image-Turbo", origin_file_pattern="text_encoder/*.safetensors"),
ModelConfig(model_id="Tongyi-MAI/Z-Image-Turbo", origin_file_pattern="vae/diffusion_pytorch_model.safetensors"),
],
tokenizer_config=ModelConfig(model_id="Tongyi-MAI/Z-Image-Turbo", origin_file_pattern="tokenizer/"),
)
pipe.load_lora(pipe.dit, "./models/train/Z-Image-Turbo_lora_distill/step-20.safetensors")
prompt = "a dog"
image = pipe(prompt=prompt, seed=42, rand_device="cuda")
image.save("image.jpg")

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@@ -1,4 +1,4 @@
import torch, os, argparse, accelerate
import torch, os, argparse, accelerate, copy
from diffsynth.core import UnifiedDataset
from diffsynth.pipelines.z_image import ZImagePipeline, ModelConfig
from diffsynth.diffusion import *
@@ -50,6 +50,13 @@ class ZImageTrainingModule(DiffusionTrainingModule):
"direct_distill": lambda pipe, inputs_shared, inputs_posi, inputs_nega: DirectDistillLoss(pipe, **inputs_shared, **inputs_posi),
"direct_distill:train": lambda pipe, inputs_shared, inputs_posi, inputs_nega: DirectDistillLoss(pipe, **inputs_shared, **inputs_posi),
}
if task == "trajectory_imitation":
# This is an experimental feature.
# We may remove it in the future.
self.loss_fn = TrajectoryImitationLoss()
self.task_to_loss["trajectory_imitation"] = self.loss_fn
self.pipe_teacher = copy.deepcopy(self.pipe)
self.pipe_teacher.requires_grad_(False)
def get_pipeline_inputs(self, data):
inputs_posi = {"prompt": data["prompt"]}
@@ -67,6 +74,9 @@ class ZImageTrainingModule(DiffusionTrainingModule):
"use_gradient_checkpointing": self.use_gradient_checkpointing,
"use_gradient_checkpointing_offload": self.use_gradient_checkpointing_offload,
}
if self.task == "trajectory_imitation":
inputs_shared["cfg_scale"] = 2
inputs_shared["teacher"] = self.pipe_teacher
inputs_shared = self.parse_extra_inputs(data, self.extra_inputs, inputs_shared)
return inputs_shared, inputs_posi, inputs_nega
@@ -138,5 +148,6 @@ if __name__ == "__main__":
"sft:train": launch_training_task,
"direct_distill": launch_training_task,
"direct_distill:train": launch_training_task,
"trajectory_imitation": launch_training_task,
}
launcher_map[args.task](accelerator, dataset, model, model_logger, args=args)